jeepnewb32

Hello, I have a 98 Cherokee Sport, AT, 4.0, 4x4. Picked this jeep up for $500 recently, would not start. Replaced PCM after troubleshooting, now have it running but no gauges. I have all the indicator lights and odometer but no gauges. Have checked grounds and fuses now I am at the point where I have dash and center console out, had no voltage at CCD bus at DLC, Cluster, or TCM. I pulled harness from ACM and now get voltage at DLC but still dont have 2.5 v at cluster, Any Ideas???

CCKen

How are you reading for CCD voltage at the instrument cluster? Connector C2, pin 1 to pin 9 (CCD -) and C2, pin 2 (CCD +) to 9?

jeepnewb32

Yes C2 , 1 to 9 and 2 to 9, also checked 9 to ground to be sure was good ground. O volt at
1 and 2, do have 120 ohms between them.

CCKen

That is odd to have zero volts at C2 yet see 120 Ohms. It would suggest that the CCD wiring from the IC to the PCM is intact and the termination resistors in the PCM are doing their job. What voltage did you get at the DLC pins 3 and 11?



Chrysler came out with a Technical Service Bulletin (TSB) in '99 that addresses instrument cluster problems. TSB NO: 08-15-99
SUBJECT: Erratic, Intermittent Cluster Operation/Intermittent Air Bag Warning light. DATE: May 21, 1999. THIS BULLETIN SUPERSEDES TECHNICAL SERVICE BULLETIN NUMBER 08-20-98 REV. A, DATED OCTOBER 2, 1998.

The fix was to inspect and clean corrosion from the connector pins and sockets or replace the connector (C2 I think) by slicing in the new connector to the existing harness.

Kits are available from the dealer.

jeepnewb32

2.5v

CCKen

Since you have the ACM disconnected, try checking the CCD voltages at the ACM connector. Pin 18 CCD (-) White/Black tracer wire, pin 19 CCD (+) Violet/Brown tracer wire, pin 10 ground Black/Pink tracer or Black/Yellow tracer wire.

jeepnewb32

Ok, sorry went for a drive , now I check for voltage at dlc between 3 to 11 and 4 to 11 and have 0 v but last night i did have 2.5 volts there, acm still unplugged , guess its time to start all over, will check at acm harness

jeepnewb32

OK checked ACM connector, no voltage there or at DLC now

CCKen

At the DLC, go from 3 to 4 or 5, and from 11 to 4 or 5. See diagram.

You may have zero volts because the instrument cluster is (?) the bias module, i.e., it generates 5 volts on the bus and the PCM is the termination module that converts the 5 volts to 2.49 and 2.51 volts.

If you temporarily plug the instrument cluster back in and get 2.5 volts you'll know it's the bias module.

jeepnewb32

Well you are correct sir, plugged cluster in checked between 3 & 4 at dlc =2.5
11 to 4 or 5 = 2.5v
At ACM also have 2.5 v pin 10 to 19 and 10 to 18
also checked ccd bus at RKEM and have 2.5 so have TCM, RKEM , & ACM connectors all pulled but still gauges are dead. Also my power locks dont open with the switches, they will unlock but not lock, didnt know if this would have anything to do with it but thought I'd mention it.

Thanks for all the insight so far CCken, really appreciate it.

CCKen

Don't know if you checked these yet, but...

There are two fuses that power the Instrument Cluster, Fuse 16 (IOD) in the PDC, and fuse 9 10A, in the Junction Block.

The IOD is indentified on the lid of the PDC and fuse 9 in the JB is shown in the image below.





Did you read over that bit I posted about the TSB? Inspect the pins and sockets of your instrument cluster connectors for corrosion. They will appear as black spots. You can use a tiny jeweler's screw driver to gently clean the pins and sockets, being careful not to enlarge the pin sockets. Some XJ owners have tweeked the pins a bit by carefully twisting them slightly with needle nose pliers (or equivalent) so they fit tighter in the pin sockets (cavities).

If the fuses are good and you have cleaned the connectors and the cluster still won't fire up, you may want to incorporate the new connectors per the TSB. Contact your Chrysler dealer and see if they have the kit.

jeepnewb32

Ok will check and try tweaking and cleaning the pins, will let u know. Thanks again.

jeepnewb32

Ok, installed new cluster connectors & still no gauges. Could I have the wrong ecm that I got from the salvage yard, running out of ideas.

CCKen

Inventory time....

98 PCM P/N 56041536AB - fed emissions, auto trans - 97 & 99 different part numbers.

98/99 TCM P/N 56041386AA

98/99 ACM P/N 56007323AD

jeepnewb32

Ok old pcm was P56041534 AD
salvaged pcm P56041296
Tcm & acm # are what u have above